Dead weight tank for testing the bearing value of a column



May 26, 1953 J l. w. ALCORN DEAD WEIGHT TANK FOR TESTING THE BEARING'VALUE OF A COLUMN Filed Dec. '7, 1948 FIG! ' FIG.4

INVENTbR. IRWIN w ALCORN 521M H 11;

ATTORNEY Patented May 26, 1953 DEAD WEIGHT TANK FOR TESTING THE BEARING VALUE OF A COLUMN Irwin Wyland Alcorn, Houston, Tex., assignor to The Pure Oil Company, Chicago, 111., a corporation of Ohio Application December 7, 1948, Serial No. 63,982

(Cl. Ni-84) 4 Claims.

This invention relates to an apparatus for testing the bearing value of columns and, in particular, consists of a dead weight load-applying apparatus for a column.

In underwater oil well drilling operations, it is necessary to erect a working platform over the point where the well is to be drilled so that a derrick can be erected and various operations performed in place. Before a safe working platform can be fabricated, the foundation therefor must be set in place and usually it will take the form of a pier built on piles. The piles may be of various lengths, but will normally be long enough to be driven into the bed underlying the body of water and leave a section projecting above the surface. Sound procedure calls for testing the bearing value of a pile after it is driven in order to see that it is capable of carrying its share of the load. Frequently, in drilling operations, the load for a single pile will be as high as 250,000 pounds. The difficulty of bringing so much dead weight, or a mechanical apparatus capable of applying such a load to a pile, to a point over a body of water is apparent.

Accordingly, it is a fundamental object of my invention to provide a dead weight column or pile testing apparatus which weighs only a small fraction of the load which is to be applied to a pile.

It is a second object of the invention to provide a very simple mechanical structure which can be used for testing the bearing value of columns and obviate the necessity of providing heavy mechanical apparatus for the purpose.

It is a further object of the invention to provide a simple dead weight testing apparatus in the form of a tank whereby the load applied to a column under test may be varied between substantially zero and the maximum load for which the column is to be tested.

Other objects and advantages of the invention will in part be obvious and in part appear hereinafter.

The invention, accordingly, is embodied in an apparatus which comprises essentially a tank having a longitudinal sleeve so that the tank can be slipped on to a pile to be tested, and when it is in place, be filled with water to the extent desired to apply the necessary load to the pile.

A full understanding of the invention and of its application in testing piles may be gained from the examination of the following specification and the accompanying drawing in which:

Figure 1 represents a perspective view of the apparatus in place on a pile and taken partly in section in order to show the interior structure thereof;

Figures 2, 3 and 4 represent in diagrammatic style several other forms of apparatus.

In the drawing, 10 represents a large cylindrical sheel having a conical bottom ll and a centrally disposed longitudinal sleeve i2 passing the length thereof. Sleeve I2 is integrally joined with the conical bottom at l3 and is supported along its length within the shell by braces like l4, l5, l6 and I1. Across the upper end of the tank, which may be wholly open, there is mounted at least a pair of transverse supports in the form of I-beams l8 and I9 which are arranged with their ends fastened to the outer shell Hi and cross over the open end of sleeve 12. A quick opening discharge valve 20 is provided near the bottom of the tank so that it can be drained easily of any water contained therein. Similarly, for convenience, a conduit support in the form of a bracket or clamp 21 is provided at the top of the tank to permit the attachment of a hose thereto through which water can be pumped into the tank. Because of the greater ease in filling the apparatus with a load-imparting fluid the preferred embodiment of the instant invention is, as shown in Figure 1, an open-topped vessel. In the event that a totally enclosed vessel, such as the spherical configuration shown in Figure 2, is employed to contain the load-imparting fluid an inlet means must be provided in the upper region of the vessel to admit the fluid into the container section of the vessel. As an example, a nozzle 23 or plurality of nozzles which may or may not be fitted with adjustable closure means may be utilized for this purpose.

From the diagram and the description given, the manner of using the structure can readily be determined, because it is shown in place on a pile 22 and the use of the various structural sections can be determined therefrom. Cross pieces l8 and I9 at the top of the tank make possible its support by those elements. Braces, such as l4, l5, l6 and I1 serve to hold the tank and the pile sleeve in good longitudinal alignment during its use. Bracket 21, to which a hose or conduit of any type can be clamped supports the conduit so that the tank is readily pumped full of water once it has been slipped on to a pile. When the test has been completed by filling the tank to a certain point and observing the behavior of the pile, the tank is readily emptied by the opening of the quick action discharge valve 20. When it is emptied, it is conaxis of the column. Should'the load-be'asym-; metrically applied, a false indicationofthebean ing value of the pile might beobtained because one side of the pile will be uiif'der"ceiiipress'i"onand the other under tension. \Wtli'theuseofpioper adapters, where the sleeve l2 does not fit neatly around a given pile, load canzi'be? symmetrically applied to a pile by means of this tank in controlled amount from loads which approximate only the weight of the tank up to loads which equal 'theweighfi of the tank whenit as ruu ot Walter: Theadva nt'a 'ge bfb'eing ams td-cohduct' a test under such conditions, where a cont-rolled load is applied in substantially continuous radation is obvious.

Thus, I have described anew ty-pe of column testing device for use in testing piles on'thesite Where they are beingdriver'i and, in'.particular, onthe'site Wheret-hey- "*beirigd Lii inrelatively 'deep 'wateff "Although the yentioir has been described interms' ofonly a s'pecific sin embodiment; variations thereof;particularly; n. the shape ofthe- 'tanle as shown in l- -igures- 2, '3 and 4-can 'readily be-madefi The-pr" ei'pal feature uponthe fabrication- Ora-ask, is to select a shape which permits the alignment 0a the och-- ter of gravity'of the-load -With-lie'-= xis oi -the column to be-tested anfdi in general configuration symmetrioalabout-a len'gitiidinal is indicated'." Thus} spherical;- combination conical and ellipsoidal; and'ell'ipsoidal forms as shown in- Figures '2; 3' and 4 are usefulr for th ey cam be made" a'ssymin'etrical tanks defined by 'surfaces of revolution about l *a longitudinalaJXis'L In these structures, the centerof gravity or" --tl ie tank will be placed in lin'e-yi' ith the-longitudinal axis of the column being tested} A refinement of the designis to 'leca'te the 'c'enter ct-gravity below theniiddle of the 'vessel. I haye found that the a i essentially symmetrical arrangement illustrated in Figure 1-of=-the -drawing-is cnverrient, both in ease-"of fabricatiori 'aiid pvlfitierrfierit of t load; 11 .2: w: 5.1.2.; L11; 01,33,191 i I Thus, though the '-invez ition has been described in detail with respect-' t'o on iy a siI-igle 's'pecific embodiment, the spirit and scope ther'eoftshould be apparent and the drawings Shomd b'e-take'n as illustrative and 'not restrictive- -tliereoiz- What' isclaimed isa l1 1.- An-'app'aratus for testingthe bearingsvalue of a column comprisinga vessel, theisurfaceiof said vessel being a :surface-of revolutionksym, metrical .with respect .to" its -vertical' :axis; a sub.-

4 stantially vertical longitudinally supported sleeve disposed coaxially with said axis and adapted to engage slidably with the column, the length of said sleeve being substantially equal to the length of said vessel, means for admitting a fluid into said vessel and means adjacent the upper extremity [of said sleeye for": supporting said vessel symmetrically ori the terminal section of the column.

2. A testing apparatus comprising, a vessel symmetrical about its vertical axis, a sleeve mem- -ber-of' substantially smaller cross section than said vessel extending substantially the entire 'distancebetween fthe vertically spaced extremities of saidiyes'sel'and aligned with the axis of symmetry of'said vessel, said sleeve member being 'adaptedto engage slidably a column, and means adjacent the upper extremities of said sleeve for supporting the apparatus longitudinally upon the terminal section of a substantially vertical column to apply ai oa d "thereto.

messei comprismgeh on "she/115a magi: tu'dinal inher sleeve-oi' sugb s any ret eat section-than;the shll disposed coax lly' within said shell j thereby: ;forming an ani ate space closed'at oneend, -means to hold?thej she fid sleeve in fixed-spaced" relationship" and 'a" ischarge'valve in' the closed end'of-' 'sa*id""yss'l; said vessel' 'be'ing' 5 provided was "a ma'ns fa- 50*- axial'ly supporting the vesse'lupon si -"substantially vertical-column. A: 3

4. A test: loadingapparatus fordetermining the bearing capacity of driyen piling"c'ompris'ing an elongated-vessel having afiixed-"the'rein a sleeve extending the vertical longitudin l'le'n' 'th of said vessel "along-the"axis thereof and p fle trating the bottom of said vessel thereby to ming an annulus "between said -jsleeve and I said sleeve being'h'eld infixed -iielation withsaid vesselby means of suitable mating, means" for filling said vessel with liquid' arid-a valved (nitlet adjacent the bottom of the said 'vesei,a1id'-- a means contig'uoustb the upper'nd oisaid-sleeve adapted to supportsaid apparatus upon the seminar end" or a substantially" verses-1' eatenp e When said apparatus is slidably enga e thereon." r::,.;.

vessel; 

